Since the early 1990s and the establishment of separate but parallel dialogues between the United States and North Korea (over nuclear issues) and inter-Korean relations (over potential peninsular reconciliation), there have been worries that North Korea might attempt to exploit these channels by creating a wedge in U.S.-ROK alliance cooperation. But the alliance is the main factor in the emergence of U.S.-ROK-DPRK triangular relations that has limited North Korea's capacity to improve one relationship while neglecting the other. Effective U.S.-ROK alliance cooperation makes the two countries' relationships with North Korea parallel and interactive: progress in one is likely to require progress in the other while a failure to improve one relationship will act as a limiting factor constraining the development of the other. This dynamic has proven to be true during the past two decades.

The negotiation of the U.S.-DPRK Geneva Agreed Framework in the mid-1990s was greeted with skepticism by the Kim Young Sam administration, especially as the North Koreans responded negatively to South Korean policy following the death of Kim Il Sung. But the implementation of the Agreed Framework and South Korea's central role in the Korean Peninsula Energy Development Organization ultimately created a new channel for inter-Korean relations, contributing to an easing of inter-Korean tensions in the late 1990s. In turn, the establishment of the inter-Korean summit in 2000 proved to be a catalyst for North Korea to reach out to the United States by sending Cho Myung-rok, Vice Chairman of the National Defense Commission, to Washington and to enable Secretary of State Madeleine Albright to visit Pyongyang at the end of the Clinton administration.

However, a negative turn in U.S.-DPRK relations with the inauguration of the Bush administration created constraints on Kim Dae Jung in his pursuit of a second inter-Korean summit. Ultimately, inter-Korean relations were constrained by a chill in the U.S.-DPRK relationship. Although Roh Moo-hyun was able to have a second inter-Korean summit at the end of 2007, South Korea was ultimately constrained in its attempts to promote inter-Korean economic cooperation at Kaesong by the necessity of coordination on nuclear issues with the United States through the six party talks.

With the inauguration of the Lee Myung-Bak administration, there was speculation that North Korea might again follow a policy of focusing on the United States while marginalizing South Korea (tongmi bongnam); however, the pattern described above reveals that U.S.-ROK alliance coordination imposes real limits on the capacity of North Korea to pursue progress in one relationship while trying to marginalize the other.

Developments in 2009 appear to confirm the limits of the ability of North Korea to pursue progress in one relationship while marginalizing the other. The early part of 2009 was marked by the simultaneous deterioration in inter-Korean relations and rising tensions in U.S.-DPRK relations resulting from North Korea's missile and nuclear tests. Likewise, North Korea's "charm offensive" of the second half of 2009 has been dual-pronged: former President Clinton's mission to Pyongyang to secure the release of American journalists re-opened DPRK efforts to engage with the United States, while North Korea released a South Korean held for months at Kaesong during Hyundai Asan Chairperson Hyun Jung-eun's visit to Pyongyang in mid-August.

Such a convergence in the momentum of North Korea's respective relationships with the United States and South Korea suggests that any North Korean effort to exploit differences between the United States and South Korea is being minimized. However, North Korea still resists Lee Myung-bak's efforts to place denuclearization on the agenda of the inter-Korean relationship while focusing on U.S. 'hostile policy' as an opening to place peace on the U.S.-DPRK diplomatic agenda prior to denuclearization.

Some observers see Pyongyang's focus on peace as a direct challenge to the U.S.-ROK alliance, since the establishment of a permanent peace regime on the Korean peninsula would arguably obviate the need for the alliance or for U.S. troops on the peninsula. However, precisely because these issues are at the core of the alliance, it is unimaginable that such issues could be taken up absent the closest of consultation between the United States and South Korea, further tying together prospects of improvements in both U.S.-DPRK and inter-Korean relations.

From the perspective of the United States, progress on denuclearization, peace, and normalization of relations is increasingly connected, as Ambassador Bosworth implied in Seoul immediately following his visit to Pyongyang. Ambassador Bosworth's dialogue with North Korea--and his deepened regional consultations with allies and friends--underscores the necessity of regional cohesion as a core element of the Obama administration's current approach to North Korea. Arguably, any progress in the U.S.-DPRK relationship and in inter-Korean relations is likely to be mutually reinforcing.